Blood collection protocol for burrowing owls
The purpose of bleeding burrowing owls for this project is to determine the amount of genetic exchange between
populations and, ultimately, rates of immigration and emigration in each population (i.e., how much genetic exchange
there is between a population in one study site/location and another). Sample all adults and at least one juvenile from
each nest. Wait until juveniles are ~18 days old to collect a blood sample.
Effective bleeding is done by piercing the skin and vein without going all the way through the vein. This
requires a steady piercing movement with more pressure than you may expect. However, start out not applying much
pressure until you have a feel for how much pressure is necessary. Less pressure is generally required with juveniles than
adult birds. The veins repair quickly so if you do slice through the vein (ie, pierce one side of the vein and exit the other
side) it will be OK. If you pierce the vein, you may have to switch to the other wing to get a blood sample.
Hold the bird in your lap face up with its head towards your knees. With your left hand you can stretch out the
owl’s left wing if you are right handed (or if you are left handed, use your right hand to stretch out the owl’s right wing).
You will also be restraining the owl because your hand or wrist will be across its chest.
The brachial vein stretches across the humerus bone and is clearly visible through the skin. Clean the area
around the brachial vein with rubbing alcohol. This also helps keep feathers out of the way so they don’t clog the
capillary tube and makes the vein more visible. If necessary, pump the vein by blocking it a few seconds with your
thumb. Insert the lancet at an angle (~30 degrees) with beveled end (open end) facing up (toward you). This should be a
relatively quick straight in-out movement to avoid making a large hole in the vein. If the hole in the vein is larger than
the hole in the skin, blood will pool under the skin. Remove your thumb before or while withdrawing the lancet to
prevent blood pooling under the skin. Have the capillary tube ready to suck up the blood. You need to collect at least one
half a capillary tube of blood, but collect an entire capillary tube whenever possible. Once you have filled the capillary
tube, blow the blood from the capillary tube into the collection tube. Squeeze the blow tube to expel the blood into the
collection tube. Then shake the collection tube until the blood is mixed with the buffer. The ratio of blood to buffer
should be about 1:5, but that is only a rough ratio.
Stop the bleeding with a cotton ball and clean the area if necessary. Apply pressure if necessary until the
bleeding ceases. Make sure bleeding has stopped before releasing the bird. If some feathers become tainted with blood,
wipe the feathers clean with a cotton ball and some water.
It's a judgment call on how many times you can pierce the vein in each wing, but a guideline of 2 pierces/wing is
probably wise. If you only pierce the skin (which happens if the vein is small or rolls or not enough pressure is applied),
then you may pierce again without counting that as one of the 2/wing.
Blood is stored in 1.5 ml flip-top microfuge collection tubes with about 500 ml of TES buffer (see below). The
buffer can be stored at room temperature, but freeze it if possible. Make sure to label each tube with the band # (both
FWS # and ACRAFT color band), age (AHY, HY, unk), sex (M, F, M?, F?, unk), nest identification #, date, year, and
study site. Use a permanent ink marker and write the info directly on the collection tube, and then put scotch tape over
the writing to ensure it doesn’t get rubbed off.
After piercing a bird’s vein, blood often will pool under the skin and forms a ball (a hematoma). Sometimes
these can get large and appear worrisome. However, studies have shown that birds are not affected by these hematomas
and if you re-trap a bird a day later the hematoma will be gone.
Caution: Please be extremely cautious that the blood sample from one individual owl is not contaminated with the blood
sample of another owl when collecting blood from more than one bird during a trapping session. For example, when you
touch a cotton ball with blood or your finger gets in contact with blood when sampling a bird, be super cautious when
handling the next bird. To remove all possibility of cross-contamination, use a solution with bleach to clean your hands
between birds.
Storage
Buffer storage: Store the buffer (prior to putting blood in it) at room temp (ie, 24oC). Minimize the time it spends in the
field, or in a hot vehicle.
Blood and buffer mixture storage: Store the samples in a freezer whenever possible. If a freezer is not available
immediately, store in a refrigerator until you are able to freeze the samples. If neither a freezer nor refrigerator are
immediately available, store at room temperature until samples can be frozen/refrigerated. Samples can actually be stored
for a year at room temp without being frozen/refrigerated. The main thing is to get them out of the heat as soon as
possible and into a cool place. The heat inside a car (with closed windows) can be very bad for blood samples so do not
forget to take samples out of your vehicle asap.
Supplies – available from VWR Scientific Products (1-800-932-5000):
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Lancets -- Owen Mumford Unilet (part # AT 0418, cat # 15400-032; $8.69 for 200)
Capillary tubes -- VWR Micro-Hematocrit Capillary Tubes with heparin (cat # 14705-003; $3.01 for 200)
Blowers for the end of the capillary tubes (Microcap Bulb Assembly 1-000-9000; cat # 53507-268; $0.97 each)
1.5 ml microcentrifuge collection tubes – flip-top or screw-cap (i.e., Fisher Scientific, cat# 0553871A; $135.10
for 500 tubes)
Storage boxes for collection tubes (item #R8300; $31.00 for 6 boxes that each hold 100 tubes)
Cotton balls
Rubbing alcohol
Permanent ink pen or marker for writing on collection tubes
Clear Scotch tape
Buffer - Buffer is necessary to preserve the DNA in the blood samples. Participants can make their own buffer (recipe is
below), or we can send you collection tubes already filled with buffer. Please contact Courtney Conway (contact info
below) if you would like us to send you collection tubes with buffer already in them.
TES Buffer
(100mM Tris, 100mM EDTA and 2% SES)
This buffer, when mixed at 5:1 buffer:fresh blood or tissue will protect the DNA and inhibit nuclease and
microorganisms. Samples can be stored at room temperature, refrigerated, or frozen (frozen is preferred for long term
storage and repeated freeze-thaw in not a problem).
TES Buffer recipe for 100 mls, pH 8 (from powdered chemicals):
2M Tris HCL, pH 7.5
0.5M NA2EDTA
10% SDS
Distilled water
5 ml
20 ml
20 ml
55 ml
TES Buffer recipe for 100 mls, pH 8 (from stock solutions):
Tris base
EDTA disodium salt
SDS
Distilled water
1.2 g
3.7 g
2.0 g
to 100 ml volume
Contact for Project PI:
Dr. Courtney J. Conway
USGS Arizona Coop. Fish & Wildlife Research Unit
104 Biological Sciences East
University of Arizona
Tucson, AZ 85721
ph: 520-626-8535
FAX: 520-621-8801
Email: cconway@Ag.Arizona.Edu